we'll be right back. ♪ i'm the tax man, yeah, i'm the tax man. should 5% appear to small. ♪ martha: a top republican senator is now objecting to a claim that members of his party were using the boston terror attack as an excuse to delay immigration reform. this is an important hearing on this matter that is underway right now. meanwhile things got a little bit tense yesterday after democratic senator charles schumer made these comments, watch this exchange. >> the chairman has a very open process, so a few ways to improve the bill offer an amendment in may and let's vote on it. i say that particularly to those who are pointing to what happened, the terrible tragedy in boston as i would say an excuse for not doing a bill or delaying it many months or years. >> i never said that. >> i didn't say you did. >> i never said that. >> i didn't say you did, sir. i didn't say you did. i don't mean you mr. grassley. >> chairman i don't appreciate you demeaning the witnesses that are coming here. martha: tempers flaring at that hearing. i'm joined by bob b